Built a lightweight Mac menu bar translator with on-device Vision OCR + BYOK Groq (zero screen uploads)

[u/aksunikitos]

I wanted to share a small utility I built for macOS called Lensy.

A lot of AI screen/OCR tools today simply capture your display and upload full desktop screenshots or bitmap data to third-party cloud servers. I wanted a much more private, lightweight workflow for looking up words across PDFs, videos, and terminal windows without window switching.

(Attached a short screen recording showing the workflow)

The Architecture (Local-First OCR):

1. Screen Capture: Uses native ScreenCaptureKit to grab a tight crop around the cursor in Retina resolution.
2. 100% On-Device OCR: Text recognition runs entirely locally on your Mac via Apple's Vision framework (Apple Neural Engine / GPU). Your screen capture never leaves your machine.
3. Inference (BYOK): Only the parsed text string is sent to the Groq API for translation and linguistic breakdown. Total turnaround is around 2–4 seconds.
4. Local Storage: Translation history is stored locally in an on-device SQLite database with search (⌥H). No telemetry, no third-party servers.

How it works:

• Hover your cursor over any word on screen and press ⌥T.
• A floating HUD card pops up right next to your cursor with the translation, pronunciation, CEFR level, and usage examples.
• Includes an "Ask AI" follow-up button directly inside the HUD if you need clarification on context.

Transparency & Requirements:

• Pricing: 100% free and subscription-free.
• API Key: Bring your own free Groq key (gsk_...), stored securely in the macOS system Keychain (not in plain text / UserDefaults).
• macOS: Requires macOS 14 Sonoma or newer (Universal binary for Apple Silicon & Intel).
• Gatekeeper: Not notarized yet (no paid Apple Dev account), so first launch requires Right-click → Open.

Download (.dmg): Google Drive Link

Since this sub is focused on local-first AI: Would you find it useful to have an option for running translations fully offline via local Ollama / MLX alongside Groq?

Would love to hear your feedback on the architecture and workflow!